8-Bit Comparator General Description These comparators perform an equal to comparison of two 8-bit words with provision for expansion or external enabling. The matching of the two 8-bit input plus a logic LOW on the EN input produces the output A = B on the DM74ALS520 and DM74ALS521. The DM74ALS520 and DM74ALS521 have totem pole outputs for wire AND cascading. Additionally, the DM74ALS520 is provided with B input pull up termination resistors for analog or switch data. Ordering Code: Features Devices also available in Tape and Reel. Specify by appending the suffix letter X to the ordering code. September 1986 Revised April 2000 Switching specifications at 50 pf Switching specifications guaranteed over full temperature and V CC range Advanced oxide-isolated, ion-implanted Schottky TTL process Functionally and pin for pin compatible with LS family counterpart Improved output transient handling capability Ordering Code Package Number Package Description DM74ALS520WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide DM74ALS520N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide DM74ALS521WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide SM74ALS521N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide DM74ALS520 DM74ALS521 8-Bit Comparator Connection Diagram Function Table H = HIGH Logic Level L = LOW Logic Level X = Don't Care Inputs Output EN Data A = B L A = B L L A B H H X H 2000 Fairchild Semiconductor Corporation DS006114 www.fairchildsemi.com
Logic Diagram www.fairchildsemi.com 2
Absolute Maximum Ratings(Note 1) Supply Voltage Input Voltage Operating Free Air Temperature Range Storage Temperature Range Typical θ JA N Package M Package 7V 7V 0 C to +70 C 65 C to +150 C 62.0 C/W 82.0 C/W Recommended Operating Conditions Note 1: The Absolute Maximum Ratings are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The Recommended Operating Conditions table will define the conditions for actual device operation. Symbol Parameter Min Nom Max Units V CC Supply Voltage 4.5 5 5.5 V V IH HIGH Level Input Voltage 2 V V IL LOW Level Input Voltage 0.8 V I OH HIGH Level Output Current 2.6 ma I OL LOW Level Output Current 24 ma T A Free Air Operating Temperature 0 70 C DM74ALS520 DM74ALS521 Electrical Characteristics over recommended operating free air temperature range. All typical values are measured at V CC = 5V, T A = 25 C. Symbol Parameter Conditions Min Typ Max Units V IK Input Clamp Voltage V CC = 4.5V, I I = 18 ma 1.5 V V OH HIGH Level V CC = 4.5V to 5.5V Output Voltage I OH = 400 µa V CC 2 V V CC = 4.5V I OH = Max 2.4 3.2 V V OL LOW Level Output Voltage V CC = 4.5V I OL = 24 ma 0.35 0.5 V I I Max HIGH V CC = 5.5V V IH = 5.5V Input Current B Input DM74ALS520 0.1 ma V IH = 7V, All Others I IH HIGH Level V CC = 5.5V, All Others 20 Input Current V IH = 2.7V B Input DM74ALS520 200 µa I IL Low Level Input V CC = 5.5V, B Input DM74ALS520 0.6 ma Current V IL = 0.4V All Others 0.1 ma I O Output Drive Current V CC = 5.5V V O = 2.25V 30 112 ma I CC Supply Current V CC = 5.5V (Note 2) 12 19 ma Note 2: I CC is measured with EN grounded, A and B inputs at 4.5V and outputs OPEN. Switching Characteristics over recommended operating free air temperature range Symbol Parameter Conditions From To Input Output Min Max Units t PLH Propagation Delay Time V CC = 4.5V to 5.5V A or B LOW-to-HIGH Level Output C L = 50 pf Data A = B 3 12 ns t PHL Propagation Delay Time R L = 500Ω A or B HIGH-to-LOW Level Output Data A = B 5 20 ns t PLH Propagation Delay Time LOW-to-HIGH Level Output EN A = B 2 12 ns t PHL Propagation Delay Time HIGH-to-LOW Level Output EN A = B 5 22 ns 3 www.fairchildsemi.com
Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Package Number M20B www.fairchildsemi.com 4
Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Package Number N20A DM74ALS520 DM74ALS521 8-Bit Comparator Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications. LIFE SUPPORT POLICY FAIRCHILD S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 5 www.fairchildsemi.com